Surface cleaning by pulsed UV-laser (wavelength = 193 nm) annealing in vacuo and laser-enhanced oxidation of GaSb single crystals in air are investigated by Auger and X-ray photoelectron spectroscopies. Superficial etching observed below energy densities of 100 mJ/cm2 is due to desorption of the Sb-oxides stimulated by photolysis. Above this threshold, the remaining Ga oxides are burried into the melted layer. The photolysis of the oxide also stimulates a layer-by-layer oxidation when GaSb is irradiated in air at lower energy densities (1 to 3 mJ/cm2 ).